Detachable coupling



Nov. 5, 1946. A. w. MILLER Re 22,810

DETACHABLE coUPLING original Fiied Aug. 25. 194s 2 sneetsfsheet 1 www Yalbert MW if Nov. 5,

UNITED STATE Re. 22,810 'I DETACHABLE coUPLING Albert w. Miner, Jamaica,N. Y.

Original No. 2,383,010, dated August 21, 1945,

Serial No. 499,928, August 25, 1943. Application for reissue April 26,1946, Serial No.' 665,052

' k19 Claims.

This invention relates to detachable couplings for tube or pipe and,more particularly, .to a coupling which may be applied to the tube orpipe without preliminary fitting of the tube or pipe, also inparticular, a coupling in which the predetermined gripping action isdiffused behind the flare on the tube.

Heretofore, detachable couplings have required the placing of part ofthe coupling over the end of the tube before flaring the tube, in orderthat the gripping part could be brought up against the flared section,this places the holding force at the flared section and often causes thecrystallizing of thev metal whenA metal is used,'or the tearing ordamaging of the structure at this point, in cases where plastics orother soft material is used. Another weakness in this type of couplinghas been noticed where there is vibration, which sets up a whippingaction and accelerates the crystallization or tearing or pulling out ofthe tubing. To overcome this condition there have been various attempts,such as elongating the neck of ra sleeve which is placed over the tubeto lessen the whipping laction at a critical section and somewhatdiffuse it or move the point of whip back from the flared end.

With the foregoing in view, it is an object of the present invention toprovide a detachable coupling which may be applied to a preformed flaredtube, without pre-setting any part of the coupling on the tube. A

Another object of the present 1 invention is to provide an easilyapplied coupling for tubing, in which a desired amount of the grippingforce of the coupling is diffused behind the iiarelin the tubing.

A further object of the present invention is to provide a coupling inwhich the elements provide a predetermined amount of clamping orgripping pressure on the desiredarea ,of the tube or pipe.

A further object of the present invention is to provide a detachablecoupling in which the tripping force exerted on the exterior of thetub'- ing is supported partially by the coupling on the interior of thetubing.

A still further object of the present invention (ci. 28s-ss) is toprovide a detachable coupling in which the gripping member of thecoupling'provides re'l f sultant forces acting parallel with the axis ofthe coupling and the tubing.

Another object of the invention is to provide a coupling of thecharacter described which shall be simple and ruggedln construction,easily apthe externally threaded extension i5 and is com- 1 plicable inuse, and which shall enable quick attachment yet positive gripping inapplication.

yist

2 Other objects and characteristic features of the invention willappear'from the following detailed description taken in conjunction withthei accompanying drawings wherein identical reference numerals 'areapplied to identical parts in the several figures and in which Fig. 1shows a cross section of one of the forms of a coupling in a closedposition, with the tube in place and clamped; y

Fig. 2 shows a cross section of the same form of coupling in theopen'position ready to receive the end of` a flared tube, lexcept thatboth ends are similar tube holding `types, as illustrated in Fig. 1; v

Fig, 2A is a perspective of one of the collar segments;

Fig. 3 shows a cross section in an open position of a similar couplingfor two pieces of flared tubing with a slight imodication in structure;-

Fig. 4 shows another embodiment of the coupling with a. rubber orplastic hose;

Fig. 5 shows a cross'sectional view of the coupling taken on the line5-5 of Fig. 4;

Fig. 6 shows a. still further embodiment of the coupling in crosssection, which may be applied to either metal or plastic tubing; and

Fig. 'lv shows a further modification ofthe coupling illustrated in Fig.6.

In accordance with the objects, one embodiment of this inventionconsists of a coupling Ill according to Fig. 1, in which a preformedared Vtube Ii has been inserted 'and clamped. This coupling is providedwith one end i2 for attaching to astandard fitting and the other end ilto hold the flared tube ii. The end Il of this lcoupling. is comprisedof an exteriorly screwthreaded boss i5 with a conically formed extendedtube end fitting I6 on which the flared end il of the tube i iv isfitted. A longitudinally split collar I8 composed of two or more partsis applied to the outside of the flared tube Il.v The inside portions ofthe collar i8 are lshaped :to conform with the periphery of the flareil, in-

cluding an extension i9 which lies parallelrwith the neck of the tubeand which is formed to a desired length. The opposite end of segments i8has a sharp angular portion bent inwardly beyond the end of the flared'4tube ii and positioned to abut against the shoulder of the threadedportion I9 to regulate and limit the forward longitudinal movement -ofthe segments. A nut or fastening member 20 is threadably secured toprised of' a main body portion 2l Land a hollow portion 22 having itslargest inside diameter near saaie the center of the nut and itssmallest inside diameter at the outer end so that the innercircumference of the hollow portion' conforms to the outer taper of thecollar segments.4 Thus,- it is apparent that when the coupling is in anopen position as shown in Fig. 2, the ared tubeA may be inserted intothe end of the coupling through the spread insert collar I8 and theflared end of the tube pressed up against the conically formed tube endtting I6. Threading the nut 20 forward on to the thread I causes itstapered walls 22 to press the portions I8 against the flared end I1andthe adjacent neck of the tube II. As the nut is tightened, thepressure or clamping force increases until the inner surface of collarI8 and the end I9 establish a positive hold on the periphery of thedared section and the adjacent neck of the tube. The segments of thecollar being selectively -preformedwith a predetermined arc for aparticular circle at which their edges abut to limit vtheir contractionto prevent a pressure being applied that would crush or damage a tube ofa particular composition. f

The term boss as usedA herein is to be understood as referring vto anextension or sleeve on one coupling member, and itis threaded to receivethe threaded -opening of the other coupling member. Y

It is to be noted that the inner circumference of the collar I8 isdesigned to correspond to a deiinite degree of nare on the tube IIandthat the grip on the neck of the tube adjacent to the flare may belengthened as desired; for example,

if a tube is given a flare offldegrees 37 minutes and the |base lengthof the flare is 1/4 of an inch, the spread or rise at the outerend willbe 1%4; of an inch. Therefore, if asegment ofthe collar be `used with avwall thickness that corresponds to the rise of the ilare of the tu-be(W54 of "an inch), the longitudinal base length of the outercircumference of the segment sections will -be 1/2 inch and it willtherefore overlap on the neck of the holding the flared end of a tube;also, I have shown the coupling in an open position to illustrate theeasy access that a flared tube end will f have when being inserted intothe coupling. The

tube A of an inch. The longitudinal ibase length of the angle of theinner circumference of the segments would be '1A of an inch and theextension which lies parallel to the tube would likewise be 1A of aninch. It also holds true that should it be ydesired to increase thelength of that portion of the segments which lies parallel to the neckoi the tube, this may be accomplished by increasing the thickness of thesegment wall, for example: a

segment of 1/16 of an inch in thickness wouldV provide an overlap on theneck of the tube of .333 of an inch. Likewise, the length of the grip onthe neck of the tube adjacent to the nare may be lincreased any desiredamount by providingy coupling in its open position illustrates thecollar I8 as expanded to a larger inner diameter than inv Fig. 1; thismay foe accomplished in various ways, possibly using a single springwire insert which may be placed in back of the angular portion but notto interfere with the end of the ilared tube, as illustrated at 28 inFig. 2. With such an arrangement the collar will be expanded as the nutpressure is released and will always rest lagainst the innercircumference of the inner tapered surface of the nut 20. The segmentsin their open position do not offer any obstruction to the flared endoi' the tube Il when it is inserted, as their least inner diameter is asgreat or more than the diameter of the outerend of the ilared portion oftube II. The spring wire insert is merely illustrative of a resilient"means yto hold the segments in 'an open position, as various othermethods or means may be employed. Referring to Fig. 3, note'that thecoupling has been modiil'ed to hold both flared ends of tubes II inclose proximity to each other and the section I8 of the couplingdescribed in Figs. 1 and 2 has become a separate double-ended tube endtting I6 which conforms on both ends to the angley of the ilared tubewith which it is to -be mated. Likewise, the split collar IB' has beenreshaped to double its original length and its inner centralsectionformed to conform to the periphery of both flared ends of tubesII when they are mated with the insert I6. The segments of the collarI8' are formed with two angular ends I9a which may or may not conform tothe angle of the iianges of the tubes II, but must conform to the innerface of two outer nut memis' because of contracting the said collar andan extension of the segment sections, the'out'er circumference of whichwill lie in a parallel relationship with the tube. The manner ofgripping the tube about its neck with the segments 'is very important asit relieves the flared portion of most of the tensile, torsional andvibrational stresses.. It is to be noted that normally the segments ofthe split collar I8 will bite into the flared end of the tube and willnot turn with nut 20 as it is applied. To insure the segments remainingin a xed position and prevent theml turning with the rut 20, one or morepins 24 may be inserted in the section I5 and a notch 25 may be formedin the inner periphery of the thus establish a clamping action on thetubes. When the nuts 2U. and 20 have been drawn up tightly, their willhave positioned the segments in a. tight relationship with each other aswell as holding `or clamping the two flared ends of tubes II in theinner central section of the split collar I8 as illustrated in theFigure 3. It is apparent that tubes II will'be held tightly in thisposition and that, a considerable length of gripping hold on the tubesadjacent to their nared ends is obtained. .The angle of ilare providedin tubesII is governed primarily by the torsional strain and thematerial used in the tubing as the design v illustrated in Figure 3 willhave the same gripping force on tubes I I for various angles of flarefin the tubes.

.In thc embodiments of the couplings illustrated in Figures 1, 2 and 3,the inner periphery of the portions I9 and I9a of the collar segmentswhich lie generally parallel to the neck of the tubes adjacent to theirflared ends, are formed on their inner surface with a slight taper of adesired lengthfrom a larger diameter at their outer ends to a leastdiameter at a point removed therefrom.

This slight taper of about 1 degree is provided to v y '6 terminedpressure which may be created by the nut 38 when it is drawn up tightlyon the threadaiford a vibration diffusing or absorbing' means ent. Theinnerperiphery of' the segments may be*` slightly roughened in textureto provide a better grip or clasping of the tube.

Figuresil; :2 and 3 illustrate couplings for holding tubes with iiaredends having long, smallanglesvof about l degrees. As far as holding thetubes is concerned itis unnecessary to flare the herent in theseconstructions. The'ares as illusltubes because of the powerful grippingforce intrated in these figures o! the drawings are desirable forinstallations carrying fluids under high pressure, but for installationscarrying fluids under low pressure, tubes maybe used without flaring ifa slight modication is made in the illustrated shape of the collar.segments to provide an inner longitudinal face that lies parallel withthe periphery of an unilared tube as illustrated at 31 in Figure '4, andin place of the conical portions I 6, provide a bore to receive the endof the tube.

vWhen iluid is presen-ta gasket should be inserted in a recess vprovidedin the inner periphery of the collar segments I8 and I8' or in the innerend of the bore in the face of the boss l5, to prevent leakage. beingused for cable conduits. such gaskets are not `iecessary. For serviceswhere it is desired to use relatively light weight tubes' with thinwalls, a tube insert may be used to support the clamped ends of thetubes.

Another embodiment vis illustrated in Figure 4 in which a coupling 33 isprovided with a threaded end 3| for attaching to a standard fitting andthe other end 32 is designed to grip a tube, rubber hose, plastic tube,or tube of similar characteristics. The end 32 comprises an exteriorlyscrew-threaded boss 33 and an extended nipple 34, forming the main bodyof the coupling. The nipple 34 is formed with a smooth internal bore topresent the least amount of frictional resistance to the iiow-of iluidtherethrough, whereas the external portion may be comprised oiserrations which provide a gripping area on the internal face of thetube in which it is inserted. The

' coupling also comprises a longitudinally split collar 36 made up of aplurality of segments 31 and an outer nut member 38 which is threaded onthe For other installations, such as tubes ed boss 33 of the coupling.The end of the nipple 3l is formed with a slight taper from a. leastdiameter. at its outer end to' the high point of the serrations.- Thisassists the nipple when being forced into the mouth of a tube, as itpermits the tube to be slightly expanded and, thereafter, iit snuglyover 'the exterior serrated facev of the nipple.

Likewise the end 39A of the collar 38 has a tapered portion lll which istapered in the opposite direction so that the collar will slide over theouter diameter ofthe tube as the tube is inserted therein. Thetwotapered faces. the end of the collar and the end of the nipple, forma V-shape, and, therefore, under pressure will give a progressivelyincreasing pressure from the outer edge of contact to the inner face ofthe gripping area.

When a tube is to beconnectedto the coupling, nut 3B is backed of! tothe outer end of the threaded boss 33 to the position shown in Fig,.4.

L The tube may now be forced over the nipple on the threaded boss 33 andas this occurs vthe 3| until 'its end abuts the mainsection` 32 of thecoupling. The nut is then screwed forward boss 33 of the main portion ofthe coupling. The segments 31 may be formed with an inner serrated facewhich lies parallel to and is similar in structure to the outer face ofthe nipple 3l,

whereas the outer face of the segments are formed smooth with a slope ofapproximately 5 to 15 degrees as required, depending upon the characterof the tubing toy be gripped and,there fore, the maximum amount ofpressure that is "required, The slope extends from a greater diameter atthe inner end 39 to a lesserdiameter at its outer end 39A. The outer nutvmember 38 is comprised of a main body portion I2 and a hollow portion43 having its largest diameter near the center of the nut and the leastdiameter at the outer end. The slope of the internal face conforms tothe slope of the split collar 38, usually within the range oi.' 5 to ll5degrees.'

The wall of the nipple 3l is comparatively light but suiilcient towithstand the maximumpredegradually forcing its inner serrated face intothe external surface of the tube. The gripping pressure on the tubingwill be dissipated or diiifused into a squeezing pressure, asvthepressure of the collar 36 will also'cause the tubing to bepressed intothe external serrated faceof the nipp1e34.l In a tube or pipe having aknown degree of hardness, the amount of such compression or displacementrequired is provided for by the degree -of compressive slope which isthe angle of the cooperating surfaces of the collar and the nut. forexample: if the angle be 14 degrees then the hose or tube wall thicknesswould be subjected to a net displacement of about .048 of an in ch whenthe nut is advanced about l/4 of an inch on thread 33, or in the eventthe angle was about '1 degrees and the nut were advanced about A of aninch the compression on the tube would be about the same, There isalways a xed relationship between the slope of the clamping faces andthe clamping nut thread movement.

In Fig. 4 I have illustrated a series of serrations,

on the exterior tace oi the nipple 3l and 'on the inner face of thesegments of the collar 38, itis to be noted that the serrations arearranged in y a parallel relationship -when they are to be used with arubber hose as this permits the high points of the serrations to bear onthe hose at the same point from opposite sides and thus displace orextrude the .rubber into the lower part of the serrations giving a tightgripping relationship. When the coupling is to be used for plastictubing it is desirable to place the serrations in a staggeredrelationship as the pressure on the tubing displaces the plastic into arippled or corrugated formation and the plastic retains that set evenafter removing the coupling. As in the case o! the'couplings previouslydescribed, the segments 36 are likewise selectively preformed with apredetermined arc for a particular circle at which their edges abut tolimit their contraction to prevent a pressure being applied that wouldcrush or damage a tube of a particular compositior. The arcs are, ofcourse,1 predetermined in radius or diameter as' required for use whenfastening tubes oi different characteristics due to materials.

-sion inl the boss I5.

types of rubber tubes and tubes made of plastic A still furtherembodiment is illustrated in Y Figures 6 and? in` which a coupling 50 isprovided with a threaded end I for attaching t0 a standard fitting andthe other end 52 is designed to receive tube II. The tube may have oneor more key slots I9 cut with a right angle face toward the coupling anda 45I degree face away from the coupling.A The key slots are formedaround the periphery of the tube II'.

The end 52 of the coupling is comprised of an exteriorly threaded boss53 and an internal bore 5l shaped at its inner end to receive the end ofthe tube II'. A nut 55 is threadably secured to the boss 53 and iscomprised of a main body portion 55 and a hollow portion EI'having itslargest diameter near the center of the nut and its smallest diameter atthe outer end so that the inner circumference of the hollow portion hasa taper which is usually between 5 degrees and 15 degrees.

A split collar BIJ is mounted within the nut 55 and is comprised of aplurality of segments 8i. The exterior of each section is tapered toconform to the inner circumference of the hollow portion 5l of the nut55, whereas the internal.

tace of each section 6I.' is formed parallel to the tube to be insertedtherein. On this internal face of the sections 6I there may be providedone or more raised keys 62 which are spaced in the same relationship asthe key slots 49 on the tube I I They are also shaped with a right angleface on the inner side and a 45 degree face on the outer side so thatthey conform'to the slots 48 into which they are intendedlto beinserted,

and they are approximately the same'size to insure a snug fit.

In Fig. 6; the collar 60 is held in a proper relationship with the tubeII, when in its open position by the abutment of the shoulder 1010i.'collar 80 and the outer face of the end 52 of the coupling. When vthenut 55 is advanced on the thread 53 the collar IiIl will be, contractedcausing the keys 62 to engage with the key slots 49. When the collar hascontracted sufficiently it will have an'unobstructed longitudinalforward movement and the shoulder Ill will pass into the recess 69 inthe face of the coupling. The longitudinal forces provided to the tubebyI further advancing of the nut 55 will force the end of the tube IIinto a tight leak proof seal with the internal -bore 54. It is to benotedfthat it is not necessary to remove the nut 55 from the thread 53as an expansion wire` or springmay be incorporated in the split collar60 and when the nut is turned'back to the position indicated in Figure 6the collar 60 will open sufllciently to allow ,the tube I I to beremoved or inserted as the case may be. Upon threading the nut forwardon thread 53 'the collar 80 will be brought into a snug engagementwith'the tube II and will force the tube into a tight fitting positionwith the internal portion of the coupling. It is to be noted thatshoulder 1c abuts shoulder 59 when the tube has been forced to apredetermined and limited position in a longitudinal direction.

It will be apparent that a similar result may be obtained with theconstruction shown in Fig. 2 by the engagement of the tapering ends ofthe segments I8 with the wall of the A slight modiilcation of thisembodiment is conical depres-kv indicated in Figure 7 in which the nut55 has formed on the portion 51 a lip 55 having a face 66 at rightangles to the axis of the coupling and the collar GII has two steps inits outer periphery i forming a face ET which is also at right angles tothe axis of the coupling. In operation, as the nut 55 is tightened andafter it has squeezed the collar 60 snugly against the surface of tubeII' `the nut 55 whereas in Figure 7, vvalthough the same forces arepresent an additional direct longitudinal force is brought to bear onthe tube when the two faces 66 and Elmeet as nut 55 is moved forward `onthread 53.

All the embodiments of this invention include the use of a plurality ofsegments of a split. collar with tapered surfaces. An important featureof this invention is that theseucollar segments may be so constructedthat when they are squeezed together by bingforced into the smaller endof the tapered nut as it is advanced on the cooperating threads, theiredges will abut at a predetermined point and thus prevent any increaseof pressure on the tube regardless of the amount of turning torque thatymaythereaiter beapplied in tightening the clamping nut. Thus theconstruction permits of determining in advance the maximum amount ofpressure that can be applied to the tube when attaching it to thecoupling. Such positive control is especially important When it -isdesired to connect tubing of the softer metal alloys and for tubing madeof vplastic materials, as such tubing becomes seriously deformed orcrushed when subjected toexcessive clamping pressure.

The embodiments of the'invention herein disclosed are merelyillustrative and maybe modified and departedy from in many ways withoutdeparting from the spirit and scope of the invention as pointed out inand limited solely bythe appended claims.

What is claimed is:

1. In a detachable tube coupling including a screw-threaded boss, a tubeend fitting, a collar comprised of a plurality of longitudinal segmentsthat act independently of each other, said segments having exteriortapered surfaces, a screwthreaded binding nut to engage the threadedboss` of the saidv coupling, said binding nut having a portion embracingthe exterior surfaces of said segments, and means to control and limitthe longitudinal movement .of said segments, said binding nutcontracting the said segments to squeeze saidv segments intogrippingrelation on a tube, and said binding nut and said segmentsoperating to force said tube into a firm connection with the said tubeend tting. f

2. In a detachable tube coupling including a screw-threaded boss, atube. end iltting, a collar comprised of a plurality of longitudinalsegments that act independently of eachother, said segments havingexterior tapered surfaces, a screwthreaded binding nut to engage thethreaded boss of the said coupling, said binding nut having a portionembracing the exterior surfaces of said segments, and means to controland limit the lon- :y the tube and thus clampingI the tube with a sureto prevent the crushing of the tube. and said binding nut and saidsegments operating to force said tube into a rm connection with the saidtube end fitting.

'3. In a detachable tube coupling including a screw-threaded boss, atube end fitting, a collar comprised of a plurality of longitudinalsegments that act independently-of each other, said segments havingexterior tapered surfaces, a screwengage the screwthreaded binding nutto threaded boss of the said coupling, said-binding nut having a portionembracing the exterior surfaces of lsaid segments, means to control and*limit the longitudinal movement of said segments, the said binding nutcontracting the said segments to squeeze said segments into a. grippingrelation on a tube, means provided to limit their casio exteriorlyscrew-threaded boss having a shoulder, a collar comprised of a.plurality of longitudinal segments that act independently of each other;en internally threaded binding nur beving an, interior tapered surfaceconforming to the exterior surfaces of said segments, a tapered nippleshaped to receive a. preformed fiaredend of a tube, one end of saidsegments bearing against the shoulder of the threaded boss to controland limit the forward longitudinal movement of said segments, saidbinding nut when turned forward contracting the said segments to apredetermined limit, to Squeeze said segments .into a gripping relationalong the flared surface or the tube and along the aree directly behindthe flared section of the tube, said shoulder of the threaded bosshaving stop means and said segments being formed to co-operate with saidstop means to limit the rotation of said segments contraction and theresulting gripping pressure to prevent the crushing ofthe tube, saidbinding nut and said segments operating toforce said tube into a firmconnection with the said tube end fitting, and a resilient means-toexpand the said segments to hold their outer tapered surfaces in'juxtaposition with the interior tapered surface of thebinding nutwhen,said binding nut is retracted, the outer ends of said segmentshaving a Sliht taper adjacent tothe tube to be gripped.

to provide a gradually increasing pressure on the tube whereby thevibrational stresses are diffused and transferred -to the coupling.

4. In' a detachable tube coupling including an exteriorly screw-threaded`boss, a collar comprised of a plurality of longitudinal segments withpredetermined exterior tapers, a binding nut having' an interior taperto conform to the exterior taper of the segments, the binding nut havingalso an internal screw thread to engage the threaded boss of thecoupling, the sgments-co-acting to'grip the tube when the binding nut'isturned forward on the threads of the boss, said'segments having apredetermined set -for a particular circle at which theirrledges abut tolimit their contraction, the binding nut contracting the segments uponpredetermined and limitedpressure:

5; In a detachable tube coupling including an as the said binding nutsqueezes the said segments into a gripping relation on the tube.

'1.' In a detachable tube coupling according to claim 6 said shoulderbeing undercut to provide for limited forward longitudinal movement ofthe segments after said segments have been contracted into a grippingrelation on the tube to force the dared end of said tube/tightly againstthe tapered nipple of the coupling.

8. In a detachable coupling including an exteriorly screw-threaded bosswith a shoulder and y having an extended nipple for insertion into theend of a tube, a collar comprised of a plurality of longitudinalsegments that act independently of each other, each segment beingprovided with complementary lip portions along the longitu- .dinal edgesso that the plurality of segments form a complete enclosure, saidsegments having also exterior tapered surfaces, a binding nut having aninterior taper to conform to the exterior faces in' juxtaposition withthe interior tpered exteriorly screw-threaded boss having a Jshoulder, acollar comprised of s pluralitg oflongisurfacooftlletubeandalongtheareadirectly behind the flared sectionof the tube. alresilient means to expand the said segments to holdvtheir outer tapered surfaces in juxtaposition with the interiortaperedsurface of the binding nut when said binding nut is retracted, and saidsegments.

having an extended'preformed outer portion adjacent to thetube to begripped, with means to diifuse the vibrational stresses' on thecoupling.

8. In a detachable tube coupling including an 7s collar surface` of thebinding nut when said binding nut is, retracted. said shoulder of thethreaded boss l stop means and said segments being formed to co-operatewith said stop means to ,limit the rotation of said segments as the said'binding nut the said segments into a v gripping relation on the tube. f

f s. In o amenable tube couplingA including en exteriorly screw-threadedboss and having an extended nipple withexterior serratlons for'insertioninto the end -of a tube, a collar comprised of a plurality oflongitudinal segments that act independently of each other and withserrations along 'their inner face, said segments having exteriortapered surfaces, a binding nut having an interior taper to conform tothe exterior taper of the segments, the binding nut having also aninternal'screw thread to engage the threaded boss of the coupling, theserrations of the segments and the serrations of the nipple coacting togrip the tube, the binding nut contracting the Segments upon the tubeand thus lclamping the tube upon the nipple, said segments beingselectively preformed to the arc of a particular circle to limit theircontraction, and the resultantl gripping pressure., to prevent thev fcrushing of the tube.

1o. ma detachable tube coupling including, e

compred of a plurality of double-ended l segments that act independentlyof each other, a pair of tubeV couplings which have a screw,- threadedboss and socket to form aunion, the exterior ends f each segment beingtapered, the said tube couplings having inner tapered surfaces at theirouter ends which conform to the taper of the segments, the exteriortapered surfaces of the double-ended segments co-acting with theinterlorltapers of the tube couplings to contract, to a predeterminedlimit, the said segments to grip the tubes, and a resilient means toexpand the `said double-ended segments to hold their outer taperedsurfaces in juxtaposition with the interior tapered surfaces o! saidcouplings.

11. In a detachable tube coupler including, a collar comprised of aplurality of double-ended segments that act independently of each other,a double-ended male insert. a pair of tubecouplings which have ascrew-threaded boss and socket to form a union, the central innersurface of said double-ended Lsegments cut out to -conform to the flaredends of a'pair of oppositely positioned inserted flared tubes and theexterior ends of each segment tapered. a double-ended male bearinginserted between the said flared ends of the two tubes, the said tubecouplings having inner tapered surfaces at their outer ends which con--the vibra-tional stresses on the coupling.

12. In a detachable coupling for a tube having one or more key slots cutin its periphery including an exteriorly screw-threaded bossand havingalso a bore to receive a tube, a collar com prised of a plurality oflongitudinal segments having exterior tapered surfaces that actindependently of each other, an interiorly screwthreaded binding nuthaving an extended portion with an interiontaper to conform to the taperof the segments, said segments having keys formed integral therewith onthe inner surfaces thereof and conforming in size and shape to the keyslots formed on the said tube, the binding nut when turned forward onthe threaded boss contracting. to a predetermined limit, the saidsegments by means of the tapered co-acting surfaces to squeeze said`keys into their respective key slots to hold the tube and coupling in atightly key anchored relation.

13. Ina detachable tube coupling including an exteriorly screw-threadedboss and having a bore, a collar comprised of a plurality oflongitudinal segments having exterior tapered surfaces that actindependently of each other, said taper being comprised of two or moresteps with a sharp right angie face or shoulder between, a 'binding nuthaving an interior taper with steps in opposite relation to conform tothetaper of the segments, means to key a tube and. the segments L inpredetermined relationship, and a means to f predetermine and limit thedegree of lateral clampingpressure and the degree of sealing pres-- 12 Ysegments having exterior tapered surfaces that act independently of eachother, an interiorly screw-threaded binding nut having an extendedportion with an interior taper to conform to the taper of the segments,means to key a tube and the` segments ina predetermined relationship,and means to predetermine and limit the degree of lateral clampingpressure and the degree of sealing pressure exerted in a longitudinaldirection, to prevent the crushing of the tube.

15. In a detachable coupling for a tube or other elongated member,comprising a body member.

having a screw-threaded boss, a collar composed of a plurality oflongitudinal segments that are movable independently of each other, saidcollar being adapted to receive one end of said elongated member and thesegments thereof having exteriorly tapered surfaces, a binding -nuthaving a portion for screw-threaded engagement with said boss and aportion for receiving said segments having its inner surface embracingthe exterior surfaces of said segments whereby upon threading togethersaid binding nut and said boss said segments are contracted so as tocause them to] grip said elongated ymember, and resilient means forexpanding said segmental collar when theA binding nut is retracted.

16. In a detachable coupling for tubes or other elongated members,including two telescoping screw-threaded coupling members, and a collarcomposed of a plurality of double-ended segments that act independentlyof each other,vtheend portions of the exterior surfaces of said segmentsbeing tapered and said coupling members having interior tapered surfaceportions whichconform to the tapered surface portions of they segments,wherebyv upon threading said coupling-members together said taperedsurface portions of said coupling members act on said tapered surfacewith said boss, saidbinding nut surrounding said segments with a portionof its interior surface embracing the exterior sui aces of the segmentswhereby upon threading said binding nut to said boss the segments arecontractedvso as to grip the end portion ofsaid elongated member and tobe urged forwardly as they are thus contracted, and vmeans restrictingsuch forward movement of the segments until, they are contracted intogripping engagement with said elongated member and then permitting thesegments to be moved forwardly during the continued threading of saidnut to the boss.

18. A structure according to claim 17 in which resilient means isprovided for expanding said segmental collar when the binding nut isretracted.v

. 19. In a detachable tube coupling including a body member having ascrew-threaded boss and a tubeend fitting, a collar composed of aplurality of longitudinal segments that act independently of eachother-and adapted to receivev the lend portion of a tube with the end ofthe tube engaging said tube end tting, said segments having exteriorlytapered surfaces, a bind- 13 ing nut for screw-threaded engagement withsaid boss, said binding nut surrounding said segments with a portion ofits interior surface embracing the exterior surfaces of the segmentswhereby upon threading said binding nut to said boss the segments arecontracted so as to grip the end portion of said tube and to be urgedforwardly as they are thus contracted, and means restrict- 14. ing theforward movement of the segments until they are contracted into grippingengagement with the .tube and then during the continued ,threading ofsaid nut to the boss permitting the segments to be moved forwardlythereby to force the tube into a. firm connection with said tube endfitting.

ALBERT W. MILLER.

